Recentering Adapter Cam for Exit Latch Home Position Return
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Solution Overview
Problem
Exit device assemblies face issues with components failing to return to their home positions, leading to incomplete extension or retraction of the latch, which affects the locking and unlocking functionality.
Innovation Solution
A recentering adapter is introduced, comprising a housing, cover, support plate, and cam mechanism with a biasing element, which ensures proper alignment and return of drive spindle and tailpiece to their home positions, facilitating complete operation of the latch mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If clutch operation is used to transfer power from trim or pushbar assembly to extend/retract the latch, then the latch can be actuated, but the components may fail to return to home position causing incomplete latch extension or retraction
Solution Approach 1:
A recentering adapter is introduced as an intermediary component between the clutch mechanism and the drive spindle. This adapter includes a cam mechanism and biasing element that actively returns the drive spindle to its home position, mediating the interaction between the clutch and drive spindle to ensure proper positioning without increasing overall system complexity
Solution Approach 2:
The recentering adapter performs preliminary action by pre-positioning the drive spindle at the correct home position before clutch engagement occurs. The biasing element and cam mechanism ensure the drive spindle is already in the correct orientation to receive power transfer from the clutch, preventing positioning errors before they can affect latch operation
2Reliability
If components fail to return to home position, then the latch cannot fully extend or retract, but adding recentering mechanisms increases device complexity
Solution Approach 1:
The recentering function is merged with the existing clutch housing structure. The recentering adapter integrates the cam mechanism, biasing element, and drive spindle support into a single unified component assembly that fits within the existing clutch housing, combining multiple functions (power transfer, recentering, and positioning) without adding separate complex mechanisms
Solution Approach 2:
The recentering adapter is designed to be self-regulating through the biasing element that automatically returns the drive spindle to its home position. The cam mechanism and biasing element work together to self-correct positioning errors without requiring external control systems or additional complex actuation mechanisms
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The recentering adapter enhances the reliability of the latch mechanism by ensuring it fully extends or retracts, improving the operational efficiency and functionality of the exit device assembly.
Implementation Method 1
a biasing element having a first leg and a second leg... the biasing element can engage the cam to bias the cam to the home position
Data Source
AI summary
A recentering adapter for biasing a position of at least a drive spindle coupled to a first cam and a tailpiece coupled to a second cam of an exit device assembly. The recentering adapter can include a support plate having one or more protrusions and a cam having one or more arms. At least one leg of a biasing element can engage an arm of the cam as the cam is rotated away from a home position, while another leg of the biasing element remains engaged with the support plate. A cover plate and support plate can include apertures that provide first and second aperture pairs. A handing body can engage one of the first and second aperture pairs such that the handing body is positioned to engage an arm of the cam so as to limit a direction the cam is rotatable away from the home position.